In the manufacturing and testing of printed circuit boards, and in some instances during the repair of printed circuit boards, components must be removed from the board. This naturally involves melting the solder holding the pins to the board. There are several techniques for melting the solder which mounts the pins and subsequently removing the component from the board.
Probably the oldest method of solder removal is the use of a braided copper solder wick. This is the method used by home hobbyists, and is tedious when used with components with numerous pens, to the point of being nearly impossible when hundreds of pins are involved. One principal problem is that if the component is not easily removable after wicking each pin, it is not apparent which pins are still stuck.
A second method utilizes a soldering iron heating element in conjunction with a tiny vacuum which sucks the solder out of the holes as it is melted. This is more effective than the wicking technique, but it is nevertheless very tedious and time-consuming when a number of pins are involved and suffers from the same drawback of not knowing which pin is stuck if the component will not come out at its socket.
Yet another method involves use of a prior patent obtained by applicant entitled METHOD FOR SOLDERING AND DESOLDERING ELECTRONIC COMPONENTS, U.S. Pat. No. 4,771,932, issued Sept. 20, 1988. This technique involves the use of a very wide and sharp soldering blade which is applied to all of the pins in one row at once, so that one edge of the component can be pried up, with the blade subsequently being applied to the opposite line of pins, with that side being pried up, and so forth, until the component is worked out of its socket. For components having pin rows no longer than an inch and a half or so, this technique will work, and is much superior to those previously mentioned. However, since some components have pin rows several inches long, such as an edge connector which may have a 14" triple row of pins, this technique is ineffective.
There is a need for an apparatus and a technique for desoldering all of the pins of a single dual-space or triple-space in-line package up to several inches long, without affecting the other portions of the circuit board.